In the preparation of bread, noodles, cakes or other foods, the step of mixing or kneading flour with water constitutes a large proportion of the entire preparation process and often has a direct influence on the cost and quality of the final product. Generally, in the step of mixing and kneading the flour with added water, macroscopic mixing with laminar flow or shearing is done first by adding a comparatively small quantity of water. Thereafter, microscopic mixing by diffusive mixing is done to obtain a homogeneous system.
FIG. 1 is a graph schematically showing an example of a conventional mixing/kneading step. In the graph, the logarithm of the standard deviation .sigma. of samples indicating the degree of mixing is shown along the ordinate and the mixing time is shown along the abscissa. Generally, in a convection mixing area I in an initial stage of the mixing step, the convection mixing predominates. In a convection/shearing mixing area II in an intermediate stage, the mixing proceeds ordinarily by convection and shearing. In a diffusion/mixing area III in a final stage, the effects of diffusive mixing appear. As specifically shown in FIG. 1, the flour is rendered wet and viscous in the intermediate area II, and its resistances against the deformation is increased. Thus, macroscopic mixing by shearing consisting of a combination of rolling, folding, crushing and compressing is required. Consequently, considerable time, equipment, labor costs, and other expenditures are required for this step.
In the preparation of bread, noodles, cakes and other foods using the foregoing process, it is time-consuming also to homogeneously mix the flour with eggs, butter, milk, or a viscous component such as those obtained by straining steamed pumpkins, carrots, potatoes, spinach, ground fish meat and beef for the purpose of improving the taste of enhancing the nourishment. Further, it is difficult to homogeneously mix such additives as sugar, salt, vitamins, preservatives, and coloring agents. These mixing operations require considerable time, equipment, labor costs, and other expenditures.
In view of the foregoing, it is an object of the present invention to provide a method which permits reduction of time, equipment and expenditures such as power expenditure required for the step of mixing or kneading edible flour with water and/or other components.